"We hope that a new leadership will act to benefit co-operation with Russia and to benefit the region as a whole," he said.

The president of neighbouring Afghanistan, Hamid Karzai, said he was saddened at the news of Mr Niyazov's "unfortunate" death.

Mr Karzai said Mr Niyazov "played a key role in strengthening bilateral relations" between the two countries.

Many in the region fear it is less the bizarre style of his rule and more the lack of political institutions that could prove to be the real legacy of Mr Niyazov, says the BBC's Natalia Antelava in Almaty, Kazakhstan.

Education, healthcare and society generally are regarded as having crumbled under his rule.

"President Niyazov was in effect the state and what he decreed on any subject, from politics, to culture to science, was absolute law," says Michael Hall, Central Asia project director for the International Crisis Group.

A mostly Muslim nation, Turkmenistan boasts the world's fifth largest natural gas reserves as well as substantial oil resources.

Cult of personality

Mr Niyazov became Communist Party chief of what was then a Soviet republic in 1985 and was elected first president of independent Turkmenistan in 1991.

In 1999, he was made president-for-life by the country's rubber-stamp parliament.

During his reign, Mr Niyazov established a cult of personality in which he was styled as Turkmenbashi, or Leader of all Turkmens.

He renamed months and days in the calendar after himself and his family, and ordered statues of himself to be erected throughout the desert nation.

Cities, an airport and a meteorite were given his name.

Mr Niyazov was intolerant of criticism and allowed no political opposition or free media in the nation of five million people.

His laws became increasingly personal. It was forbidden to listen to car radios or smoke in public, or for young men to wear beards.

An alleged assassination attempt in 2002 was used to crush his few remaining opponents.

All candidates in the December 2004 parliamentary elections, at which there were no foreign observers, were his supporters.